Achillea plant named ‘HEARTTHROB’

ABSTRACT

A new cultivar of  Achillea  plant named ‘HEARTTHROB’ that is distinguishable by basal branching, upright and spreading plant habit, fern-like foliage which is grey-green in color at time of flowering, inflorescences which consist of bright red ray flowers and yellow disc flowers forming a contrasting eye. Flowering of ‘HEARTTHROB’ commences in late June and continues until October on plants which are 45 cm in height and 35 cm in width after 1 year of growth from an initial cutting.

Genus and species: Achillea millefolium.

Variety denomination: ‘HEARTTHROB’.

BACKGROUND OF THE NEW PLANT

The present invention relates to a new and distinct cultivar of Achilleacommonly known as Yarrow, which is grown as an ornamental plant for usein the garden and landscape. The new cultivar is known botanically asAchillea millefolium and will be referred to hereinafter by the cultivarname ‘HEARTTHROB’.

Achillea is a genus within the family Asteraceae in which the commonlyreferred to “flower” is botanically the inflorescence which is comprisedof outer showy ray florets surrounding smaller disc florets. Theinflorescences of Achillea are borne in clusters or corymbs.

‘HEARTTHROB’ arose and was selected from an ongoing breeding programwhich is conducted by the inventor at the inventor's nursery in Penhow,Wales, United Kingdom. The breeding program commenced in 2014 with theaim of developing new and improved commercial varieties of Achillea.Each year's breeding cycle consists of controlled pollination betweenchosen male and female parents including unnamed and unreleasedseedlings retained from previous breeding cycles. Seed from each year'scycle is harvested and sown in the fall, and new seedlings are raisedand evaluated in the following summer.

‘HEARTTHROB’ is a seedling selection that resulted from the controlledpollination in 2015 of a single plant of the inventor's proprietaryAchillea seedling code AC 89 (unreleased and unpatented) as the femaleparent, using pollen from a single plant of the inventor's proprietaryAchillea seedling code AC 201 (unreleased and unpatented) as the maleparent. The inventor selected ‘HEARTTHROB’ in 2016 for its combinationof large and colorfast bright red blooms with contrasting yellow “eyes”and which are borne on strong stems, and blue-green fern-like foliage.

‘HEARTTHROB’ was first asexually propagated by the inventor in Penhow,Wales, United Kingdom in 2016 using the method of shoot tip cuttings.Since that time under careful observation ‘HEARTTHROB’ has beendetermined uniform, stable and true to type in subsequent generations ofasexual propagation.

SUMMARY

The following traits have been repeatedly observed and represent thedistinguishing characteristics of ‘HEARTTHROB’. In combination thesetraits set ‘HEARTTHROB’ apart from all other existing varieties ofAchillea known to the inventor. ‘HEARTTHROB’ has not been tested underall possible conditions and phenotypic differences may be observed withvariations in environmental, climatic, and cultural conditions, however,without any variance in genotype.

-   -   1. ‘HEARTTHROB’ exhibits tight clumping basal-branching and an        upright plant habit.    -   2. The juvenile foliage of ‘HEARTTHROB’ is bright mid-green in        color, becoming grey-green in color at and after flowering.    -   3. The foliage of ‘HEARTTHROB’ is finely dissected and fern-like        in appearance.    -   4. A fully expanded corymb of ‘HEARTTHROB’ is 5.5 cm to 6.0 cm        in diameter and is comprised of inflorescences which contain ray        florets arranged around a central disc.    -   5. The ray florets of ‘HEARTTHROB’ are arranged in a single        horizontal plane.    -   6. The ray florets of ‘HEARTTHROB’ are bright red in color.    -   7. The mass of disc florets of ‘HEARTTHROB’ are yellow in color,        forming an “eye” within each inflorescence.    -   8. The flowers of ‘HEARTTHROB’ are carried on strong stiff        stems.    -   9. Flowering of ‘HEARTTHROB’ commences in mid-late June and        continues until October.    -   10. After one year of growth in a 2 gallon container, or planted        in the ground, a plant of ‘HEARTTHROB’ is 45 cm in height        (including the flowers) and 35 cm in width.    -   11. ‘HEARTTHROB’ is hardy in USDA Zone 3 (−40° F. or −40° C.).

COMPARISON WITH PARENTAL LINES AND KNOWN VARIETY

In comparison with the female parent, seedling code AC 89, ‘HEARTTHROB’is shorter and more compact in size and bears its flowers, which aresimilarly bright red in color, on shorter stems. In comparison with themale parent, seedling code AC 201, ‘HEARTTHROB’ bears bright red flowerswhereas AC 201 bears red-purple flowers.

The commercial variety of Achillea which the inventor considers to mostclosely resemble ‘HEARTTHROB’ is Achillea Plant Named ‘Pomegranate’(U.S. Plant Pat. No. 20,763). In comparison with ‘Pomegranate’, althoughthe plant habits and sizes are very similar, the ray florets of‘HEARTTHROB’ are bright red in color whereas the ray florets of‘Pomegranate’ are red-purple in color.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying color photographs illustrate the overall appearance of‘HEARTTHROB’ showing the color of foliage and inflorescence as true asis reasonably possible to obtain in color reproductions of this type.The photographs were taken from one-year old plants which were growingin-ground out of doors in Oxnard, Calif., without any pruning or use ofchemical growth regulators. The colors in the photographs may differfrom color values cited in the detailed botanical description, whichaccurately describe the colors of ‘HEARTTHROB’.

FIG. 1 illustrates a plant of ‘HEARTTHROB’ which is just coming into budin early June. At this early stage of flowering, the foliage of‘HEARTTHROB’ is bright mid-green in color.

FIG. 2 illustrates the buds and open flowers of the inflorescences of‘HEARTTHROB’ in late June. FIG. 2 also illustrates the blue-green colorof the foliage of ‘HEARTTHROB’ at flowering stage.

BOTANICAL DESCRIPTION OF THE PLANT

The following is a detailed botanical description of the new cultivar‘HEARTTHROB’. Observations, measurements, values and comparisons werecollected in Oxnard, Calif. during late June 2019 from a 1 year oldplant growing in-ground outdoors. Color determinations are made inaccordance with The 2007 Royal Horticultural Society Colour Chart fromLondon, England, except where general color terms of ordinary dictionarysignificance are used.

-   Botanical classification:    -   -   Family.—Asteraceae.        -   Genus.—Achillea.        -   Species.—Millefolium.        -   Denomination.—‘HEARTTHROB’.        -   Common name.—Yarrow.        -   Habit.—Basal-branching, upright and spreading.        -   Commercial category.—Perennial.        -   Use.—For garden and landscape.        -   Suggested commercial container size.—4-inch, 1 gallon, 2            gallon containers.        -   Parentage.—Achillea millefolium ‘HEARTTHROB’ is a seedling            selection resulting from the controlled cross-pollination of            the following parents. Male parent: inventor's proprietary            Achillea seedling code AC 89. Female parent: inventor's            proprietary Achillea seedling code AC 201.        -   Propagation method.—Shoot tip cuttings.        -   Rooting system.—Fine and fibrous.        -   Time to develop roots (range).—14 to 21 days are needed for            an initial cutting to develop roots.        -   Temperature to develop roots (range).—The recommended air            temperature is 20° C. to 21° C.        -   Crop time (from planting a rooted cutting).—6 to 8 weeks to            produce a budded plant in a 1-quart container. 12 to 14            weeks to produce a flowering plant in a 1-gallon container.        -   Plant dimensions (one year).—45 cm in height (including the            flowers) and 35 cm in width.        -   Cultural requirements.—Grow in full sun and rich, moist            moderately fertile well-draining soil.        -   Pest or disease resistance and susceptibility.—Deer            resistant and salt tolerant. Otherwise, no specific disease            or pest resistance or susceptibility has been observed.        -   Hardiness.—USDA Zone 3.-   Stem:    -   -   Branching.—Basal, typically 6 to 8 flowering stems arise            from the base.        -   Branch and flower stem shape.—Cylindrical.        -   Branch dimensions (foliage).—25 cm to 30 cm in length, 8 mm            in diameter at base, narrowing to 3 mm towards apex.        -   Flowering stem dimensions.—25 cm to 40 cm in length (to base            of corymb), 8 mm in diameter at base, narrowing to 3 mm at            corymb.        -   Branch and flowering stem surfaces.—Ribbed longitudinally.        -   Branch and flowering stem color.—147D, ribs 178B.-   Foliage:    -   -   Type (division).—Pinnatifid.        -   Arrangement.—Alternate, spiral, cauline (flower stems).        -   Internode length (range).—1.5 cm to 2.0 cm.        -   Margin.—Very finely dissected into approximately 25 pairs of            opposite leaflets.        -   Apex.—Acute.        -   Base.—Truncate.        -   Leaf attachment.—Sessile.        -   Leaf angle.—Acute, close to 45 degrees, between adaxial            surface and stem.        -   Leaf color (both surfaces, juvenile foliage prior to            flowering).—141C.        -   Leaf color (both surfaces, at and after flowering).—N138B.        -   Leaf shape.—Lanceolate.        -   Leaf dimensions.—5 to 7 cm in length, 18 mm in width at            base.        -   Leaf venation.—Pinnate.        -   Vein color (both surfaces).—Indistinguishable from leaf            color.        -   Leaf surface (both surfaces).—Faintly puberulent.-   Inflorescence:    -   -   Inflorescence type.—Indeterminate compound corymb consisting            of small single inflorescences comprising ray florets, disc            florets, receptacle and phyllaries.        -   Corymb quantity per plant.—25 to 30.        -   Corymb shape.—Flattened dome.        -   Corymb dimensions.—8 to 10 cm in width, 3 to 4 cm in height.        -   Corymb peduncles.—Dimensions (primary peduncles, stem to            lowest corymb): 5 cm in length, 1.5 mm in diameter.            Dimensions (secondary peduncles, subtending pedicels): 1.0            cm to 2.5 cm in length, 1.0 mm to 1.5 mm in diameter. Shape:            Cylindrical. Color: 146D. Surface: Lightly pubescent; hairs            fine, white, less than 0.5 mm in length.        -   Inflorescence pedicels.—Dimensions: 2 to 4 cm in length, 1.0            mm to 1.5 mm in diameter. Pedicel color: 146D. Pedicel            surface: Lightly pubescent; hairs fine, white, less than 0.5            mm in length.        -   Inflorescence quantity per corymb (average).—50 to 80.        -   Inflorescence diameter (fully opened).—9 mm.        -   Inflorescence depth.—5 mm.        -   Inflorescence aspect.—Upright.        -   Inflorescence colors (when fully developed).—Ray florets:            Ranges between 42A and 45C. Disc florets (massed in central            disc): 23B.        -   Fragrance.—Musty.        -   Blooming season.—Late June to October.        -   Lastingness of inflorescence (range).—10 to 14 days on the            plant, persistent.-   Bud:    -   -   Shape.—Ovoid.        -   Dimensions.—3 mm in diameter, 3.5 mm to 4.0 mm in height.        -   Color.—147B.        -   Surface.—Glabrous.-   Ray florets:    -   -   Ray floret arrangement.—Rotate, single whorl.        -   Quantity.—5 per inflorescence.        -   Aspect.—Horizontal.        -   Corolla tube dimensions.—2.5 mm in length, 0.5 mm in            diameter.        -   Corolla tube color.—180A.-   Ray floret petals:    -   -   Shape.—Circular except some petals exhibit 3-lobed apices.        -   Surface (both surfaces).—Glabrous.        -   Apex.—Round, occasionally emarginate (3-lobed).        -   Margin.—Entire.        -   Dimensions.—4 mm in diameter.        -   Color (both surfaces).—Ranges between 42A and 45C.-   Disc floret:    -   -   Disc diameter.—3.0 cm.        -   Disc color (mass of disc florets).—23B.        -   Disc floret quantity.—Approximately 20.        -   Disc floret shape.—Tubular.        -   Disc floret dimensions.—6 mm to 7 mm in length (including            corolla tube), 1 mm in diameter.        -   Disc floret corolla.—5 lobed, color N155D.        -   Disc floret petals.—5. Dimensions: 5, 2 mm in length, 0.5 mm            in width. Color (both surfaces): 23B. Surface (both            surfaces): glabrous. Apex: Rounded. Base: Truncate. Margin:            Smooth, entire.-   Receptacle:    -   -   Shape.—Slightly convex; diameter 3 cm, height 0.5 cm; color            146D.-   Phyllaries:    -   -   Description.—Appear as paper like bracts or scales which            subtend the ray florets and the outermost disc florets.        -   Quantity.—Approximately 15.        -   Shape.—Lanceolate.        -   Dimensions.—2.5 mm in length, 1 mm in width.        -   Apex.—Acute.        -   Base.—Truncate.        -   Margins.—Entire.        -   Surface texture (both surfaces).—Glabrous.        -   Color (both surfaces).—146C.-   Reproductive organs:    -   -   Ray flowers.—Androecium (stamens, filaments, anthers,            pollen): Absent. Gynoecium: Pistil: 1, 3 mm in length,            diameter less than 0.5 mm. Stigma: Bifid, 1 mm in length,            color 157D. Style: Cylindrical, 1.5 mm in length, less than            0.5 mm in diameter, color 157D. Ovary (observed immature            only, barren): Inferior, ovate, length less than 1 mm,            diameter less than 0.5 mm, color 157D.        -   Disc flowers.—Androecium: Stamens: 5, fused at base.            Filaments: Length 1 mm, diameter less than 0.5 mm, color            white. Anthers: Cylindrical, length 0.7 mm, diameter<0.5 mm,            color 8C. Pollen: Moderate, color 15A. Gynoecium: Pistil: 1,            2 mm in length, diameter less than 0.5 mm. Stigma: Bifid, 1            mm in length, color 157D. Style: Cylindrical, 1 mm in            length, less than 0.5 mm in diameter, color 157D. Ovary            (observed immature only): Inferior, ovate, length less than            1 mm, diameter less than 0.5 mm, color 157D.-   Seed: None observed to date.

We claim:
 1. A new and distinct cultivar of Achillea plant named‘HEARTTHROB’ as described and illustrated herein.